The first version of NL for personal computers was developed in the early ‘90s as a tool for switching power supplies design. Since then NL has evolved into the Microsoft Windows®-based NL4, which has been used extensively by world-class engineers in different fields of electronics for almost 10 years. NL5 is the first version to be publicly available.
NL5 is circuit simulator software is a software that helps you to design non linear electronic circuits in a easy way .
Qucs (speak: kju:ks) is a circuit simulator with graphical user interface designed by Michael Margraf and distributed as a free software . Qucs abreviation from Quite Universal Circuit Simulator is able to perform many different kinds of simulation (e.g. DC, s parameter).
Qucs circuit simulator has a very nice interface and is not so complicate to use . You can use Qucs for drawing circuit diagrams for your projects or to simulate designed projects .